As is known, the periodontal ligament injection (“PDL”) is an accepted intraligamentary injection modality for primary anesthesia for one or two teeth. It is also used as a supplement to infiltration or block techniques. The PDL technique entails use of a small amount of anesthetic to produce instant anesthesia. In particular, an ultra-short needle is placed in the gingival sulcus on the mesial and distal surfaces and advanced along the root surface until resistance is met. Then the needle is advanced further to make contact and dispense more anesthetic liquid. This allows the numbing of the tooth without the patient feeling the process. The technique's primary advantage is that it provides pulpal anesthesia for 30 to 45 minutes without an extended period of soft tissue anesthesia. Moreover, because only a small amount of liquid anesthetic is injected at the site of the periodontal ligament (which inherently has limited blood circulation) PDL can be used in patients with bleeding disorders.
Various syringes and techniques have been proposed and used in the prior art for effecting PDL and there are even computer controlled anesthetic delivery systems, e.g., “The Wand” offered by Milestone Scientific, of Livingston, N.J. Such prior art syringes, techniques and systems, while suitable for their intended purposes, nevertheless leave something to be desired from one or more of the following standpoints: trauma, patient fear of needles, simplicity, cost, ease of use and effectiveness. Thus, a need exists for a low cost, simple device for readily accomplishing a periodontal ligament injection with minimal, if any patient discomfort. The subject invention addresses that need.
In addition, the subject invention also provides a device and method of use for injecting a liquid anesthetic into the gum and underlying tissue of a patient with less pain than accomplished with conventional needle syringes.